 To understand how the blow moulding process works.  To be able to identify the processes used in the creation of different plastic products.  To apply your knowledge and successfully approach an exam style question based on compression moulding.  To create an information sheet that you can use for revision guidance later.  You could be asked about the various Industrial Processes used to manufacture products. It’s important to understand not only the process but the application.

 You have explained the process step by step in an easy to read way (imagine you are explaining this to Year 7 students).  You have given an overview about how it is currently used and what specific materials are used with it (e.g. PET plastic).  You have weighed up the advantages and disadvantages of manufacturing with this method.  You have the three subtitles; overview, applications and process.  You have included some images of it’s current applications.  Key Words: Compression, thermosetting, slug, hydraulic, former.

 The mould is heated up and a “slug” or piece of plastic is placed into the mould to warm up.  The upper mould moves upwards and the plastic piece (in this case a tray) is removed.  When the plastic hits the right temperature the hydraulic press begins to move down.  As the upper and lower mould meet, the plastic is compressed into the shape of the mould. Moulding through the force of compression is another very common industrial process. The materials used are melamine formaldehyde, phenol and urea. These materials can be formed into different shapes through applying both heat and pressure, other plastics do no have these properties. This is the main way to shape thermoset plastics. AdvantagesDisadvantages The process is a lot simpler compared to other methods of production. Unsuited to complex design – the design needs to be simple to be effective under the press. The cost makes it fairly inexpensive to produce products this way. Some of the components used in compression moulding are subject to breakage. Like the ejector pin, repetitive use can cause breakages and expensive repairs. Very little waste compared to other methods e.g. injection moulding ( which has sprues and run off). It also takes longer to cure the plastic – it will take 3 – 4 minutes for the process to occur at best, often a lot longer. Injection moulding takes 2 minutes.